Fl_Nice_Slider(int X, int Y, int W, int H, const char *L=0);

function Create
       (X, Y, W, H : in Integer;
        Text       : in String)
    return Nice_Slider;

procedure Draw
       (This : in out Nice_Slider);

function Handle
       (This  : in out Nice_Slider;
        Event : in     Event_Kind)
    return Event_Outcome;